Multifunctional benefits of sainfoin mixtures: Effects of partner species, sowing density and cutting regime

Abstract

Abstract Grass–legume mixtures have proven successful at improving the sustainability of grasslands. Their ability to suppress unsown species is particularly important for sainfoin ( Onobrychis viciifolia ), a forage crop with valuable bioactive compounds, yet low competitiveness. In this 3‐year study, the suitability of six partner species cultivated in mixtures with sainfoin at different annual numbers of cuts and partner sowing densities were evaluated. Mixture yields outperformed average monoculture yields by 31%, reduced the ratio of unsown species by 65% and increased the symbiotic N 2 fixation up to 158 kg ha −1 . A key finding of the study was the highly differential patterns of development of the partner grass species over the 3 years. These patterns of development had a large effect on the persistency of the proportion of sainfoin in the mixtures, which varied in the third year between 17% (when grown with Dactylis glomerata ) and 38% (with Lolium perenne ). These findings contribute to the further development of sustainable grass–legume systems, as evidence for the successful cultivation of sainfoin as an alternative legume species can help diversification, and knowledge of mixture development supports more persistent legume proportions.